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 3.091 Intro. to Solid-State Chem. PS 1

 3.091 Introduction to Solid-State Chemistry - Fall 2012

Problem Set 1

Problem set quiz scheduled for September 11th, 2011

1.  Determine the amount of oxygen (in gram) required to convert 50 g of C2H6 completely 

into CO2 and H2O. (Use your Periodic Table.)

2.   A sample of the chemical compound iron (III) nitrate, Fe(NO3)3, weighs 16 g. How many 

oxygen atoms are in this sample?

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 3.091 Intro. to Solid-State Chem. PS 1

3.  How many atoms are in 15.3 cm3 of mercury (at room temperature)?

4.  Calculate the atomic weight of an element (X) given the following data:24 X: 24.000 amu at 0.7870 fractional abundance26 X: 26.000 amu at 0.1017 fractional abundance25 X: 25.000 amu at 0.1113 fractional abundance

5.   Ammonium nitrate, NH4NO3, is a white crystalline solid used for gun powder and as

fertilizer. Determine the number of moles of NH4NO3 in 35.8 g ammonium nitrate.

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 3.091 Intro. to Solid-State Chem. PS 1

6.  Calculate the molecular weight (in amu) of the following compounds:

(a) PbSiF6 · 4H2O

(b) CaCrO4 

(c)  NH3 

(d) CH3CH2OH

7.  Determine the number of gold (Au) atoms in 13g gold in 300K.

8.  Determine the number of atoms per cm3 of silicon.

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 3.091 Intro. to Solid-State Chem. PS 1

9.  Solid NH4NO3 (ammonium nitrate (decomposes on heating to 400°C, forming N2O gas

and water vapor, H2O.

(a) Formulate a balanced equation for this reaction.

(b) Calculate the number of grams of H2O that will form on decomposition of 0.1 mole of 

ammonium nitrate.

10.  Calculate the number of moles of nitrogen dioxide, NO2, that could be prepared from 0.35

mol of nitrogen oxide and 0.25 mol of oxygen.

() () () 

Identify the limiting reagent and the excess reagent in the reaction. What would happen

to the potential yield of NO2 if the amount of NO were increased? What if the amount of 

O2 were increased?

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 3.091 Intro. to Solid-State Chem. PS 1

11.  Calculate the mass of hydrogen chloride that can be produced from 10.0 grams of 

hydrogen and 10.0 grams of chlorine.

() () () 

 What would have to be done to increase the amount of hydrogen chloride produced in the

reaction?

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 3.091 Intro. to Solid-State Chem. PS 1

12.  The thermite reaction, used to weld rails together in the building of railroads, is described

by the following equation.

() () () () 

Calculate the mass of iron metal that can be prepared from 150 grams of aluminum and

250 grams of iron(III) oxide.

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 3.091 Intro. to Solid-State Chem. PS 1

13.  Tantalum metal is produced by the reaction of potassium heptafluorotantalate (K2TaF7)

 with elemental sodium (Na) in a reactor heated to 850°C. The by-products are potassium

fluoride (KF) and sodium fluoride (NaF).

a.   Write a balanced equation for the reaction.

b.   A reactor is charged with 222 kg of K2TaF7 and 6.66 kg of Na, and the reaction isallowed to go to completion. Calculate how much tantalum is produced. Express

 your answer in kg.

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 3.091 Intro. to Solid-State Chem. PS 1

14. Chlorine has two isotopes, 35Cl and 37Cl. For the anion, Cl- of isotope 37Cl specify 

the following:

a.  Number of protons, n p =

b.  Number of electrons, ne =

c. 

Number of neutrons, nn =

15.  Metallothermic production of zirconium involves the reaction of sodium withzirconium tetrachloride according to the following reaction

ZrCl4 + aNa →  bNaCl + cZr

a.  Balance the equation and specify the values of a, b, and c.

b.  Calculate the amount of zirconium produced if a reactor were charged with

111 kg of ZrCl4 and 11 kg of Na.

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 3.091 Intro. to Solid-State Chem. PS 1

16. The thermite reaction (see problem 12) releases 850 kJ/mole of iron(III) oxide.

Calculate the amount of heat released from 80 grams of a stoichiometry mixture of 

iron(III) oxide and aluminum.

17.  Calculate the enthalpy of atomization per unit volume for Li, Na, K, and Rb.

Express your answer in units of pressure. Use the information in the periodic

table.

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 3.091 Intro. to Solid-State Chem. PS 1

18. Make a plot of first ionization energy versus element for the two rows of the

periodic table that begin with Li and Na.